1. Technical Field
The present invention relates to a pointer structure.
2. Description of the Related Art
There is a known vehicular pointer device having a display, such as a liquid-crystal display (LCD), arranged in a center of a dial plate for a rotary pointer. In the case such a display is disposed frontward of a dial plate for the ordinary rotary pointer, the display can be laid out at or around a center of the dial plate without interfering a view of the display with the pointer.
However, in the case where the dial plate is to indicate important information such as vehicle speed and the display is to show comparatively less significant information such as current time or so, the dial plate is desirably disposed frontward of the display in a manner improving the visibility of the dial plate.
In the pointer device in a type as shown in FIGS. 5A and 5B, an LCD 610 is provided backward of the dial plate 600 formed thereon with an indicator showing, for example, vehicle speeds so that the LCD 610 backward is exposed through an aperture 601 formed in a center of the dial plate 600. Furthermore, the pointer device includes a pointer 620 for pointing an indicator on the dial plate 600, a circuit board 630 carrying electronic components thereon, and an internal mechanism 640 mounted on the circuit board 630 to rotate the pointer 620 (see Patent Document 1, for example).
The pointer 620 is provided extending along from the internal mechanism 640 to the back and main surfaces of the dial plate 600 through, in order, a backside of the LCD 610, an outer periphery of the LCD 610 and a gap between the LCD 610 and the dial plate 600. Namely, the pointer 620 is in a generally S-shape that is folded through between the dial plate 600 and the LCD 610. With this structure, the pointer 620 is not obstructive to a view of the LCD 610 despite the LCD 610 is disposed backward of the dial plate 600.
In the meanwhile, the pointer 620 is desired to emit light spontaneously in order to improve its visibility. In this case, it can be contemplated that, for example, a plurality of LED light sources are provided on the circuit board 630 in a manner surrounding a rotation shaft of the internal mechanism 640 and, moreover, the pointer 620 is formed from a light guide member as its pointer main body so that the light received from the light sources closer to the internal mechanism 640 can be guided to a pointer visualizing portion closer to a tip of the pointer main body. Further, a pointer bend portion of the pointer main body used in such a spontaneous light pointer device is provided with a reflection surface for internal reflection.
FIGS. 6A and 6B are essential-part side views showing a reference example of a spontaneous light pointer in which reflection surfaces are provided respectively at pointer bend portions of a pointer main body.
A pointer main body 501 shown in FIG. 6A is formed in a generally S-form as mentioned before and has a plurality of pointer bend portions 503a-503d. For example, the pointer bend portion 503a closer to a pointer base end, i.e. closest to a light source, is provided between a light guide portion 505 closer to a light source and a light guide portion 507 closer to a visualizing portion, as shown in FIG. 6B. The pointer bend portion 503a has at its outer corner an outer reflection surface 511 formed inclining at approximately 45 degrees so that a ray of light from the light source can be incident thereon. In addition, the pointer bend portion 503a has at its inner corner an inner reflection surface 513 formed parallel with the outer reflection surface 511. Accordingly, the outer reflection surface 511 has a normal line 515 given parallel with a normal line 517 of the inner reflection surface 513. Thus, a linear ray of light 509 emitted from a light source and traveling parallel with an axis X of the light guide portion 505 enters the outer reflection surface 511 and reflects thereon, and then becomes a reflection ray of light 521 propagating to the light guide portion 507 closer to the visualizing portion.